THE PROCESS OF REPRODUCTION. 451 



withstanding their name, are born from eggs, as well as birds, fishes, 

 and reptiles. 8 This principle also excludes that supposed production 

 of organized beings without parents (of worms in corrupted matter, for 

 instance,) which was formerly called spontaneous generation ; and the 

 best physiologists of modern times agree in denying the reality of such 

 a mode of generation. 7 



Sect. 2. The Examination of the Process of Reproduction in 



Vegetables. 



THE extension of the analogies of animal generation to the vegetable 

 world was far from obvious. This extension was however, made ; 

 with reference to the embryo plant, principally by the microscopic 

 observers, Nehemiah Grew, Marcello Malpighi, and Antony Leeuwen- 

 hoek ; with respect to the existence of the sexes, by Linnaeus and his 

 predecessors. 



The microscopic labors of Grew and Malpighi were patronized by 

 the Koyal Society of London in its earliest youth. Grew's book, Th( 

 Anatomy of Plants, was ordered to be printed in 1670. It contains 

 plates representing extremely well the process of germination in various 

 seeds, and the author's observations exhibit a very clear conception of 

 the relation and analogies of different portions of the seed. On the 

 day on which the copy of this work was laid before the Society, a 

 communication from Malpighi of Bologna, Anatomes Plantarum Idea, 

 stated his researches, and promised figures which should illustrate 

 them. Both authors afterwards went on with a long train of valuable 

 observations, which they published at various times, and which contain 

 much that has since become a permanent portion of the science. 



Both Grew and Malpighi were, as we have remarked, led to apply 

 to vegetable generation many terms which imply an analogy with the 

 generation of animals. Thus, Grew terms the innermost coat of the 

 seed, the secundine ; speaks of the navel-fibres, &c. Many more such 

 terms have been added by other writers. And, as has been observed 

 by a modern physiologist, 8 the resemblance is striking. Both in the 

 vegetable seed and in the fertilized animal egg, we have an embryo, 

 chalaz<%, a placenta, an umbilical cord, a cicatricula, an amnios, mem- 

 branes, nourishing vessels. The cotyledons of the seed are the equiva- 

 .ent of the vitcllus of birds, or of the umbilical vesicle of sucking-beasts : 



' O 



'' Bourdon, p. 221. T Ib. p. 49. 8 Ib. p. 384. 



